Case Summaries

Compressed Gas Tears Skin, Penetrates Body

A scuba diving high-pressure hose ruptures, causing air under pressure to inject into arm. (2013)

>Reported Story

>The boat driver was helping one of the divers. He held the first-stage regulator with his left hand and opened the tank valve with right hand. At that moment the high-pressure hose ruptured, and a jet of gas under pressure made a hole in the boat driver's left hand.

>His hand started to bleed and appeared to be full of air. We stopped the bleeding by applying pressure, and we stopped the air from spreading further by applying a bandage at armpit area. We massaged his arm, pushing the trapped air to his hand. This helped a bit; we saw some bubbles coming out of his hand.

>We called for an ambulance and administered oxygen during the time it took us to return to the harbor, approximately 20 minutes. The ambulance were there when we arrived.

>I recommended that his boss to take him to the recompression chamber, but he told me the doctors would take care of him. I later asked about his state of health, and his boss told me he is OK and ready to go back to work.

>Comments

>The injury described above is rare, especially outside of an industrial setting. Certain terms do need to be clarified for discussion purposes. In the diving vernacular any reference to high pressure (HP) is related to the compressed gas in the cylinder at 3,000 psi. Any reference to low pressure (LP) relates to the intermediate pressure that results from reduction of high pressure in the first stage. Typically this can range from 120 psi to 140 psi. Clinical references designate any pressure at and above 100 psi as HP. It has been established that pressure at a minimum of 100 psi can penetrate unbroken skin.1 These wounds require immediate medical treatment no matter how benign they might appear.

>In the industrial setting the possible materials that can be injected at HP include but are not limited to compressed gas, oil, grease, solvents, paints and diesel fuel. There are, of course, greater concerns with the petroleum products and other chemicals due to their toxicity and potential tissue damage. The risk of an inflammatory reaction from surrounding tissues and infection is quite high.

>In the diving environment compressed gas is obviously the most likely injectible. Industrial workers who sustain these injuries are generally inexperienced or unfamiliar with the devices they are using or servicing. With divers, familiarity may lead to a certain level of complacency. Despite fewer potential complications there is still a risk of secondary injuries that can result from any HP injection injury.

>Common injection injury sites are the palm or fingers of the nondominant hand. Injection into a finger(s) can be particularly problematic. The fingers cannot accommodate a large volume of any material due to limited tissue compartment space. The immediate insufflation and swelling can cause vascular compression, which can severely compromise circulation. The palm of the hand or other similar sites can accommodate the same volume with less risk of circulatory issues. However, a larger volume can produce the same risk of vascular compromise.

>While compressed gas poses less risk from toxicity or surrounding tissue damage compared with other possible injected substances, it is not benign. Along with the compressed gas, fragments of hose, brass fittings and bacteria from the skin or environment will be injected into the wound simultaneously. This is part of the mechanism for a high infection risk.

>It is unknown if there was any previous problems or concerns with the HP hose on this regulator. It is also unknown if a visual inspection would have offered any suggestion of hose failure. It is still worthwhile to remember to inspect all hoses and consider periodic replacement. Please discuss these issues with a local certified repair technician.

>Proper first aid should include bleeding control and urgent transport to the nearest medical facility. For a compressed-gas injection, surface oxygen is of little benefit as it would not expedite the absorption or elimination of the injected gas. Treatment in a hyperbaric chamber is not an appropriate first choice for treatment for this type of injury. The bystanders made an effort to express the gas through the injection site by massaging the arm. This is not recommended. They may have inadvertently forced the gas into other areas or into the fingers. Forcing the gas into the fingers could further complicate the injury, as explained previously. Some HP injection injuries may require surgical intervention to reduce pressure and to clean the wound. Thorough cleaning and disinfection is best left to the medical professionals.

>This is a very rare injury, but diligence and forethought will likely reduce the occurrence. Do not underestimate the energy released with the rapid expansion of compressed gas. Cases like the above should not increase fear but rather remind us to be respectful of the potential consequences of inattention.